1. Field of the Invention
This invention relates to gas seals and specifically relates to non-elastomeric secondary seals for use in gas turbines.
2. Background Art
Gas turbines normally operate at great rotational speeds and higher temperatures. Shafts of typical gas turbine engines run up to rotational speeds of approximately 25,000 RPM. Temperatures are encountered in the range of 800.degree. C. (1500.degree. F.).
Conventional means for sealing the seal rings in a gas turbine seal can not be used because of the high temperature at high rotational speeds. For example, elastomeric O-rings can not be used to seal each of the rings to the respective shaft or housing because such rings would melt under the high temperatures.